How to Do Testing in Tableau

Building a beautiful, interactive Tableau dashboard is only half the battle. A dashboard can look stunning, but if the data is wrong, the calculations are misleading, or it takes forever to load, it’s not just useless - it's dangerous. This article breaks down how to thoroughly test your Tableau workbooks to ensure they are accurate, reliable, and user-friendly before you publish them.

Why Bother Testing Your Tableau Dashboards?

Skipping the testing process is tempting, especially when deadlines are tight. However, taking the time to validate your dashboard is a non-negotiable step that protects your credibility and ensures your organization makes decisions based on trustworthy information. Thorough testing directly leads to:

• Accuracy and Integrity: It confirms that the numbers on your dashboard match the source systems. You’re building a bridge between raw data and business insights, and testing ensures that bridge is structurally sound.
• Stakeholder Trust: When an executive points to a number on your dashboard, they need to trust it implicitly. If they find one incorrect metric, they’ll doubt every other number you present. Testing is the foundation of that trust.
• Functionality: Dashboards are meant to be interactive. Testing makes sure that your filters, actions, parameters, and navigation buttons all work as expected, providing a smooth and intuitive user experience.
• Improved Performance: A slow-loading dashboard gets ignored. Performance testing helps you identify and fix bottlenecks, ensuring your users can get the information they need without frustrating delays.
• Better User Experience (UX): Good testing goes beyond data. It helps you check that the dashboard is easy to understand, visually clear, and logically laid out for your target audience. You built it to provide answers, and good UX ensures users can find them easily.

The Core Types of Tableau Testing

Effective testing isn’t a single action, it’s a multi-layered process. Think of it as checking your work from different angles to catch different types of errors. Here are the core types of testing you should perform on any Tableau project.

1. Data Validation Testing

This is the most critical layer. If the underlying data is wrong, everything else you build on top of it will be wrong, too.

• Source vs. Tableau: The simplest but most important check. Pull a benchmark report directly from the source system (e.g., Salesforce, Google Analytics, or a SQL database) for a specific time period. Create a simple text table in Tableau with the same metrics and dimensions and verify that the grand totals match perfectly. If they don't, the issue is likely in your data connection, joins, or initial filters.
• Joins and Relationships: If you've joined multiple tables, check for unintentional row duplication. A common culprit is a many-to-many relationship that inflates your numbers. Create a simple view with a record count from each table to ensure the logic is sound.
• Data Types: Make sure Tableau has correctly identified your data types. Are dates being read as dates? Are numerical IDs being incorrectly interpreted as measures? You can verify and change these in the "Data Source" tab.
• Null Values: How are nulls handled in your data? Should they be zero, or should they be excluded? Make a conscious decision and check that your visualizations reflect it correctly.

2. Calculation Testing

Tableau’s calculated fields are powerful, but it’s easy for a misplaced parenthesis or incorrect aggregation to throw your numbers off. The best way to test calculations is to isolate them.

• Build a "QA Worksheet": Create a new worksheet specifically for testing. Place the dimensions you're calculating against on the rows, and then add your original measure and your new calculated field to the text table. This makes it easy to compare values side-by-side.
• Check with an External Tool: For a handful of rows, perform the calculation manually in Excel or Google Sheets. Does your result match what Tableau is producing? This is especially important for complex calculations involving Level of Detail (LOD) expressions or intricate IF/THEN logic.
• Aggregate at Different Levels: Does your calculation work correctly when viewed by day, month, and year? Does it make sense at both a single product level and the overall category level? Use Tableau's hierarchy features to quickly test your calculation at various levels of granularity.

// Example LOD for testing
// Does {FIXED [Customer ID] : MIN([Order Date])} accurately find
// each customer's first purchase date?

// QA step: Create a list of 5 customers, manually find their first
// order date in the source data, and compare it to the calculation's output in Tableau.

3. Functional Testing

This phase is all about interacting with the dashboard like an end-user would. Simply put: you need to click on everything.

• Filters and Parameters: Test every single filter and parameter. Apply them individually and in combination. Do they filter the data correctly? Does a "Reset Filters" button clear all selections properly? Look for any illogical combinations that might break the view or show no data.
• Dashboard Actions: If you've set up actions (Filter, Highlight, URL), trigger each one. Does clicking on a state in a map correctly filter the bar chart of cities? Does the "View Details" button correctly link to another dashboard or an external URL?
• Navigation: If your workbook has multiple dashboards, test the navigation buttons or tabs. Is the flow logical? Are users able to easily move from a high-level summary to more detailed views and back again?
• Tooltips: Hover over different data points. Do the tooltips display the correct, helpful information? Check for any formatting errors or missing fields.

4. Performance Testing

A high-functioning but slow-loading dashboard can be a project-killer. Tableau has a fantastic built-in tool to help you diagnose performance issues.

• Use the Performance Recorder: In Tableau Desktop, go to Help > Settings and Performance > Start Performance Recording. Interact with your dashboard - change filters, click on different visuals - and then Stop Performance Recording.
• Analyze the Results: Tableau will open a new workbook showing a detailed timeline of every action it performed. Pay close attention to the "Executing Query" and "Computing Layout" bars. Long query times might indicate an overly complex data source or inefficient calculations. Long layout computation times might mean you have too many marks (data points) on a single view.
• Common Optimizations: Based on the recording, you can explore solutions like using data extracts instead of live connections, simplifying calculations, reducing the number of marks on a view, or aggregating data at a higher level where possible.

5. Usability and UI/UX Testing

This is where you move from "does it work?" to "is it useful and easy to understand?" This type of testing is most effective when you get a fresh pair of eyes on your dashboard.

• The "Five Second Test": Show the dashboard to a colleague for just five seconds. Then hide it and ask them: "What was this dashboard about? What was the most important number you saw?" Their answer will tell you if your main KPIs and visual hierarchy are effective.
• Check for Clarity: Are your chart titles clear and descriptive? Are the colors used logically and accessible for color-blind users? Are there helpful instructions or legends? Avoid jargon and assume your user isn't as deep in the data as you are.
• Get User Feedback: The best way to test usability is to hand the dashboard over to one of its intended users. Don’t explain it - just ask them to find a specific insight or answer a question. Watch where they click, where they hesitate, and what questions they ask. Their confusion points are your opportunities for improvement.

6. Security Testing

If your dashboard includes sensitive data and uses row-level security (RLS) or user filters, you must verify that these permissions are working correctly. One user should never be able to see another user's data unless they're explicitly supposed to.

Tableau makes this easy. In the bottom-right corner of Tableau Desktop, you'll see a "Filter as User" button. You can select specific users or groups from your Tableau Server/Cloud setup and preview the dashboard exactly as they would see it. Cycle through a few different users and roles to confirm they can only see the data they're authorized to access.

Final Thoughts

Treating testing as a final, critical phase of your dashboard development process is what separates good analysts from great ones. Integrating these different types of validation - from the source data all the way to the end-user experience - ensures that your final product isn't just visually appealing but is also accurate, performant, and genuinely useful for making data-driven decisions.

For teams looking to simplify their reporting process, building and testing dashboards in complex BI tools can be a major time sink. That’s why we created Graphed. Our platform allows you to connect all your marketing and sales data sources in one place and then generate dashboards simply by describing what you need in plain English. We handle the data connections, query writing, and visualization, providing you with real-time, accurate reports without the manual build and debugging process.